Buruli (also known as Bairnsdale) ulcer is a skin disease caused by the bacterium Mycobacterium ulcerans. The toxins made by the bacteria destroy skin cells, small blood vessels and the fat under the skin, which leads to ulceration and skin loss.
These bacteria are found naturally in the environment – for example, they have been detected in mosquitoes, vegetation and possum poo from some possum species in areas where there are cases of Buruli ulcer.
It is not known how people become infected, although it is thought that mosquitoes may play a role in transmitting the infection. Buruli ulcer is not spread from person-to-person.
The number of cases in Victoria varies widely from year to year, but numbers have been increasing each year from 2013 to a peak in 2018.
Symptoms of Buruli ulcer
The progression of symptoms can include:
- A spot that looks like a mosquito or spider bite forms on the skin (most commonly on the limbs).
- The spot grows bigger over days or weeks.
- The spot may form a crusty, non-healing scab.
- The scab then disintegrates into an ulcer.
- The ulcer continues to enlarge.
- Unlike other ulcers, this ulcer is usually painless and there is generally no fever or other signs of infection.
- The infection may sometimes present with no ulceration but with localised pain, swelling and fever, raised lumps, or thickened or raised flat areas of skin.
Locations of Buruli ulcer outbreaks
Buruli ulcer has been reported in 33 countries around the world. Affected areas include rural West Africa, Central Africa, New Guinea, Latin America and tropical regions of Asia.
In Australia, Buruli ulcer most commonly occurs in localised coastal areas of Victoria.
There are three recognised levels of risk in the areas where Buruli ulcer is endemic (constantly present in the community) in Victoria:
- The highest risk is associated with the active transmission areas of Rye, Sorrento, Blairgowrie and Tootgarook on the Mornington Peninsula.
- There is a moderate risk associated with areas in the Bellarine Peninsula (Ocean Grove, Barwon Heads, Point Lonsdale, Queenscliff), and the Frankston and Seaford areas.
- There is a low risk associated with the rest of the Bellarine and Mornington Peninsula, the South Eastern Bayside suburbs and East Gippsland.
Recent cases of Buruli ulcer
Cases in 2019 from Aireys Inlet on the Surf Coast and the Geelong suburb of Belmont, suggest these are emerging areas of local transmission.
More recently, several non-coastal suburbs in Melbourne’s inner north have been recognised as a potential area of risk. Several cases have occurred in Essendon, Moonee Ponds and Brunswick West areas of inner Melbourne.
While they had travelled to known risk areas for Buruli ulcer, genetic analysis of bacteria isolated from these cases suggest a common source of infection in the area. The risk of transmission in these areas is considered low.
Diagnosis of Buruli ulcer
Buruli ulcer is usually diagnosed by a doctor, based on:
- medical history
- travel history – if you have travelled to an area associated with Buruli ulcer
- physical examination – to identify a slowly enlarging, painless ulcer
- swabs or biopsy taken from the ulcer, which are tested in a laboratory.
Treatment for Buruli ulcer
Most Buruli ulcers can be treated with a course of specific oral antibiotics. Surgery is sometimes used in combination with antibiotic therapy.
If surgery is required, a small amount of surrounding healthy tissue is also cut out to make sure the infection is completely removed. Depending on the extent of surgery, skin grafts may be needed to close the wound.
Sometimes the ulcer can return after surgery, requiring another course of antibiotics or an operation (or both).
As the ulcer gets bigger with time, early diagnosis and prompt treatment can minimise skin loss.
Prevention of Buruli ulcer
Although the exact cause of infection in humans is not known, it makes sense to protect yourself from potential sources of infection such as soil and insect bites.
Suggestions to reduce the risk of infection include:
- Clean up outdoor areas where mosquitoes like to breed – anywhere water can collect. Such as pot plant containers, buckets, tin cans, discarded tyres, and any other untreated, freshwater sources (such as gutters, water tanks, pet bowls, bird baths, fishponds).
- Cover or overturn trailers, wheelbarrows, boats, tools and children’s playground toys to avoid water collection.
- Wear gardening gloves, long-sleeved shirts and trousers when working outdoors.
- Avoid insect bites by using suitable insect repellents.
- Protect cuts or abrasions with sticking plasters.
- Promptly wash and cover any scratches or cuts you receive while working outdoors.
- See your doctor if you have a slow-healing skin lesion.
It is important to remember that the risk of infection is low, even in those areas where the infection is endemic (constantly present in the community).
Where to get help
This page has been produced in consultation with and approved by:
Department of Health and Human Services - RHP&R - Health Protection - Communicable Disease Prevention and Control Unit
Content on this website is provided for information purposes only. Information about a therapy, service, product or treatment does not in any way endorse or support such therapy, service, product or treatment and is not intended to replace advice from your doctor or other registered health professional. The information and materials contained on this website are not intended to constitute a comprehensive guide concerning all aspects of the therapy, product or treatment described on the website. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions and to ascertain whether the particular therapy, service, product or treatment described on the website is suitable in their circumstances. The State of Victoria and the Department of Health & Human Services shall not bear any liability for reliance by any user on the materials contained on this website.